Keyboard



J. M. LoBlT 1,977,829

KEYBOARD Oct. 23, 1934.

Filed Sept. 2. 1951 15 t' INYENTOR m11 M. ah

ATTO RN EYS Patented Oct. 23, 1934 UNiTsn stares earner ortica 2 Ciaims.

This invention relates to" keyboards for line casting machines.

Among the objects ofthe invention is 'to`p1o vide an assembling mechanism having a practical keyboard with positively acting connections between the keys and the pawls or other devices which release the matrices whereby the release of a matrix is assured each time a key is operated. Another object of the invention' is to provide a keyboard in which all of the keys thereu of are responsive in a like degree to the same pressure. Other objects and advantages involving novel constructions and combinations of parts will appear in the specication and in the claims thereof setting forth a preferred embodiment of my invention which may be fully understood from the detail description and drawing in which:

Fig. 1 is an elevation through the assembling mechanism and a bank oi keys comprising a portion of a keyboard.

Fig. 2 is a rear elevation from the right oi Fig. l.

Fig. 3 is a section on line 3 3 of Fig. 1 showing the bank of keys in plan.

Fig. 4 is a section on line 4-4 of Fig. 1.

Fig. 5 shows the articulated connection between a key and a bar.

Fig. 6 is a section on line 6 6 oi Fig. 5, with the parts in normal position.

Fig. '7 is a section on line 7-7 of Fig. 5.

A common error which appears in proof is the transposition of letters because of a lag which occasionally occurs when a matrix which has been selected by the depression of a key fails, for one reason or another, to descend from its magazine in the order in which its selecting key was depressed. The fault is largely due to the sticking of parts for want of cleaning or proper lubrication, and because some machines depend upon friction for transmitting the action of a key to the matrix releasing rod. In such machines this mechanism takes the form of a rotating fric tion roller which provides the force for actuating a matrix releasing rod. It is my purpose to obviate the necessity of depending upon frictional devices so that the release of a matrix may be assured each time a key is actuated.

In the drawing I have illustrated a bank of keys comprising several keys of which keys 10. 11 and 12 are pivotally mounted upon a rod 13, and keys 14, 15 and 16 are pivotally mounted upon a rod 17. Each of these keys is provided with a nger piece 18, and the ringer pieces are mounted on the various keys according to stand- (Cl. 19g- 18) ard spacing'. As viewed in Fig. 1, the nger pieces are to the front of the shafts 13 and 17, and the rear ends of the keys have connection with rods 20, which extend upwardly and terminate just below the rear ends of fingers 21 of the matrix releasing pawls 221 The matrix releasing pawls are pivoted at 23 and are normally maintained in the position shown in Fig. 1 by means of a spring 24. Each pawl holds a matrix on the magazine` floor 25 by means of a lip 26 and when the pawl is pivoted counterclockwise, Fig. l, lip 26 is withdrawn below the surface of the magazine oor and a matrix is released. In order to illustrate the application of my invention I have shown its relation to a well-known type of matrix releasing mechanism and pawl.

The upper ends of the rods 20 are guided by means of slots 2S in a bar 29 and the rods are maintained within these slots by a strip 30. The lower end of each rod 20 is provided with a rounded projection 31 which is normally tted within a similarly rounded recessl 32 near the rear end oi a key, Fig. 5.` Thev open side of the rounded recess is suincient to permit articulation between the rod and key but prevents endwise withdrawal of the rod and key. In order that each rod and key may be separated for enabling replacement of broken and used parts it is desirable to be able to disconnect an associated rod and key without disturbing other parts of the assembling mechanism. While the engaging surfaces of the projection and recess may be bevelled so as to permit sidewise disengagement of a rod and key in one direction only, I prefer retaining the projection and recess in engagement by means oi two fingers 33` and 34, either of which may be pivoted about a pin 35 which passes through the lower end of rod 20. When the rod and key are associated the two lingers 33, 34 flank the sides of the projection 31 in the 95 manner illustrated in Figs. 1 and 6, and when it is desired to disconnect the rod and key one of the fingers may be raised as illustrated in Fig. 5 so as to permit lateral movement of the rod in respect to the key and the withdrawal of projection 31 from engagement with recess 32.

As a result oi the positive connection between the associated keys and rods it becomes possible to obtain a keyboard in which all of the keys are immediately responsive in the same degree to a like touch, that is to say, the weight oi the rods and their association with the keys are definitely measurable quantities which remain constant so that the force necessary to cause the actuation of the various keys and rods at different distances from the key pivots may be made to be substantially constant for all of the keys.

Some commonly used keyboards have as many pivot shafts for the keys as there are keys of different lengths, but I have found as a result of experimentation that the number may be reduced to two While at the same time obtaining a keyboard of which all of the keys are responsive alike to the same pressure. though the pivot shaftsA may take any desirable forms such, for example, as disclosed in United States Patent No. 1,641,543 issued September 6, 1927, which construction I prefer, I have illustrated the shaftsk as rods running through the keyboard. The keys are spaced from one another by means of collars 37, 38. For determining the normal position of the keys and pawl actuating rods, stop rods 39 and 40 are provided to therear of shafts 13 and 17, respectively.

Owing to the different lengths of keys in a single bank, as illustrated in Fig. 1, more pressure would be nesessary for operating key than for operating any other key unless provision were made to counteract for the different distances between the pivot shafts and the nger pieces of the respective keys. In order to make each key equally responsive to the same pressure, I have varied the Weight and distribution of weight of each key. For example, key 10 is designed so as to have more weight concentrated at a short distance from shaft 13 so as to compensate for the advantage gained by the longer lengths of keys 11, 12, 14, 15 and 16. Of course, the placing of the weight of the key is dependent also upon the weight of thekeys to the rear of the respective pivotal shafts as well as upon the difference in weights of the two lengths of matrix releas-f ing rods and I have taken this into c0nsideration. The manner in which I have attained proper balance of the individual keys may be understood from Fig. 1 which shows the keys variously cut. Keys of the same length may be reproduced from a pattern key. The balance of the keys is such that but a slight pressure is necessary to remove each key from its normal position resting upon either rod 39 or rod 40,

depending upon which shaft 13 or 17 the key is mounted.

While it may be readily appreciated that the balanceof the keys may be obtained in other ways such as by applying weights where necessary, the manner in which I have solved the problem is practical and explains the principles involved. By cutting the keys away or vshaping them so as to distribute their weight as desired, it does not become necessary to change the lateral spacing of the keys and the relation of one key to an adjacent key is not altered. While the form of mechanism shown and described is admirably adapted to fulll the objects primarily stated, it is to be understood that it is'not intended to confine the invention to the one form of embodiment herein disclosed for it is susceptible of embodiment in various forms all coming within the scope of the claims which follow.

What I claim is:

1;. In an assembling mechanism for line casting machines. the combination of a bank of keys having a plurality of keys of different lengths, means pivotally supporting said keys intermediate their ends, rods attached to the keys for actuation thereby, there being one rod associated with each key, means counterbalancing the weight of said rods, said keys and rods being placed so as to be equally responsive to the same pressure applied to the diierent keys at different distances from their pivotal supports, and means determining the normal positions of the keys.

2. In an assembling mechanism for line casting machines the combination comprising a bank of keys, finger pieces for said keys spaced horizontally and vertically in respect to each other, shafts pivotally supporting said keys, said shafts being less in number than the number of keys, matrix releasing rods positively connected to the keys, said matrix releasing rods being entirely supported by the keys and said keys being counterbalanced in such a manner vthat all of said keys are substantially equally responsive to the same pressure upon their finger pieces, and means for supporting the keys in normal position.

JEAN MARTIAL LOBIT. 

